Magnesium Level Management

Understanding Normal Magnesium Levels

Normal serum magnesium ranges from 1.3 to 2.2 mEq/L (approximately 0.65-1.1 mmol/L), according to the American Heart Association 1, 2, 3, 4
Hypomagnesemia is defined as <1.3 mEq/L or <0.7 mmol/L, as stated by the American Heart Association 1, 2, 3, 4

Hypomagnesemia can be classified as mild (0.76-0.64 mmol/L), moderate (0.63-0.40 mmol/L), or severe (<0.40 mmol/L), as defined by the European Society for Clinical Nutrition and Metabolism 5

Patients with cardiac arrhythmias or prolonged QTc >500 ms should maintain magnesium >2 mg/dL (>0.82 mmol/L), as recommended by the American College of Cardiology 6
Critically ill patients have a higher prevalence of hypomagnesemia (60-65%) and worse outcomes, according to the European Society for Clinical Nutrition and Metabolism 5, 6
Patients on continuous renal replacement therapy are at risk for developing hypomagnesemia, as reported by the European Society for Clinical Nutrition and Metabolism 5
Serum magnesium represents <1% of total body stores, so normal serum levels don't always exclude tissue deficiency, as noted by the American College of Physicians 6

Check for concurrent electrolyte abnormalities: hypomagnesemia commonly coexists with hypokalemia and hypocalcemia, as reported by the European Society for Clinical Nutrition and Metabolism 5
Review medications that may lower magnesium: diuretics, proton pump inhibitors, metformin, as recommended by the American College of Physicians 6